title: Archaebacterial lipid membranes as models to study the interaction of 10-N-nonyl acridine orange with phospholipids.
abstract: The dye 10-N-nonyl acridine orange (NAO) is used to label cardiolipin domains in mitochondria and bacteria. The present work represents the first study on the binding of NAO with archaebacterial lipid membranes. By combining absorption and fluorescence spectroscopy with fluorescence microscopy studies, we investigated the interaction of the dye with (a) authentic standards of archaebacterial cardiolipins, phospholipids and sulfoglycolipids; (b) isolated membranes; (c) living cells of a square-shaped extremely halophilic archaeon. Absorption and fluorescence spectroscopy data indicate that the interaction of NAO with archaebacterial cardiolipin analogues is similar to that occurring with diacidic phospholipids and sulfoglycolipids, suggesting as molecular determinants for NAO binding to archaebacterial lipids the presence of two acidic residues or a combination of acidic and carbohydrate residues. In agreement with absorption spectroscopy data, fluorescence data indicate that NAO fluorescence in archaeal membranes cannot be exclusively attributed to bisphosphatidylglycerol and, therefore, different from mitochondria and bacteria, the dye cannot be used as a cardiolipin specific probe in archaeal microorganisms.
authors.affiliation: Department of Medical Biochemistry, Medical Biology and Medical Physics, University of Bari, P.zza G. Cesare, I-70124 Bari, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Lobasso
authors.forename: Matilde Sublimi
authors.initials: MS
authors.lastname: Saponetti
authors.forename: Francesco
authors.initials: F
authors.lastname: Polidoro
authors.forename: Patrizia
authors.initials: P
authors.lastname: Lopalco
authors.forename: Jasna
authors.initials: J
authors.lastname: Urbanija
authors.forename: Veronika
authors.initials: V
authors.lastname: Kralj-Iglic
authors.forename: Angela
authors.initials: A
authors.lastname: Corcelli
mesh_terms: D000165:Acridine Orange / Q000031:analogs & derivatives* / Q000378:metabolism; D000818:Animals; D001105:Archaea / Q000166:cytology* / Q000378:metabolism; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism*; D004396:Coloring Agents / Q000378:metabolism*; D005453:Fluorescence; D006216:Halobacteriaceae / Q000166:cytology / Q000378:metabolism; D008081:Liposomes / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D008954:Models, Biological; D010743:Phospholipids / Q000378:metabolism*; D013194:Staining and Labeling
chemical_list: D004396:Coloring Agents; D008081:Liposomes; D010743:Phospholipids; C056258:N(10)-nonylacridine orange; D000165:Acridine Orange